Aerial system for wireless signaling



June 1929- c. s. FRANKL N ET AL 1,717,574

AERIAL SYSTEM FOR WIRELESS SIGNALING Filed Nov. 16. 1920 Patented June 18, 1929.

I UNITED STATES PATENT QFFICE.

cHAnLE-s s. FRANKLIN, or BUCKHURST HILL, AND WILLIAM J. PIOKEN, or soorn- END-ON-SEA, AND JOHN GLOVER- nose, or READING, ENGLAND, ASSIGNORS T0 RADIO CORPORATION or AMERICA, a CORPORATION or DELAWARE.

AERIAL SYSTEM FOR WIRELESS SIGNALING.

Application filed November 16, 1920, Serial No. 424,351, and in Great Britain November 17, 1919.

The object of this invention is to provide an improved wireless aerial system which shall have special directive properties and shall be particularly suited for duplex workingand for preventing interference from other wireless stations or from atmospherics.

It is known that if two frame-aerials or two aerial systems, each consisting of two frames at right angles and combined in a radiogoniometer, be separated by a distance comparable to the wave length of the signals to be received and be arranged to affect a common receiver in-a suitable manner, then that receiver will not vbealfected by signals from certain directions. Such aerial systms are described, forinstance, in British specifications Nos.24,098 of 1914 and 5,7 83 of 1915:- M 1m: r

5 =According-to this invention we combine with each of such frames or with each of suchisystems oftwo frames at right angles, a plain non-directive aerial in a manner that has before-been proposed for combining a plainz'aerial with a single frame aerial so that each of the systems has a polar receptiondiagram approximating to a cardioid.

Or we connect the midpoint of the radiogoniometer coils to earth, thereby giving the sameefiect.

Signals received in the two systems are then caused to act simultaneously on a common receiver situated at some point pref erably midway between the systems, arrangements being made to mis-phase the signals from the two systems relatively to each other.

\Ve have found that the whole combination so constituted has very pronouncedv and advantageous directive properties.

Thus, for example, it is possible to obtain at the same time zero for signals from one direction, maximum for signals from the opposite direction and zero for signals from two other directions which can be varied by the amount of mis-phasing. Or, alternatively, we can obtain greatly increased sensitivity for signals from one direction combined with extreme insensitivity for signals of the same Wave length coming from any direction within an are extending about 65 on either side of the direction opposed to that of great sensitivity.

The invention is illustrated in the accompanying drawing, in. which, Fig. 1 shows diagrammatically a clrcuit. arrangement embodying our invention, and Figs. 2 to 5 show 1 C being apparatus situated approximately midway between them where signals received by the separated systems are suitably combined and rectified so as to be audible in the telephones.

T113163 apparatus atv A is a' replica of that at v i I Two frames at rightangles are tuned to incoming waves by means of. variable con.- densers E and connected to the coils of; the radiogoniometer D D D Di -A search coil F is coupled to these radiogonioriieter coils and also to a circuit G connecting'to the midway station. J

Two condensers H of equal value are connected together in series and arranged in parallel with the variable condensers E, and the midpoint of'these condensers is then the middle of the frames in a symmetrical sys-- tem. These midpoints are connected together and through a coupling coil I and tuning condenser J to earth.

By suitable tuning and coupling of the search coil circuit and the plain aerial circuit a cardioid diagram of reception is obtained.

When two systems are arranged as described with cardioid polar diagrams and the currents received from them are combined in the midway station a variety of polar diagrams of reception are obtainable.

If two such systems, separated by one quarter of the wave length and disposed along the line of reception of the signals which are to be received, are combined with no misphasing, a polar diagramof reception as shown in Figure 2 is obtained.

Figure 3 shows a polar diagram of reception when the circuit X forming the connexion to the midway station for the front system B is slightly mistuned so that the inductance effect predominates to produce a lag of current of 225 relative to the applied elecis made to predominate and thereby produce a lead of currentof 22.5-relative to the applied electromotive force. 1

Figure 4 shows a polar diagram of reception when the system B is misphased to produce a lead of current of 225 and the system A misphased to produce a lag of 225.

By difierent degrees of misphasing a variety of polar diagrams of reception are ob tained in which one zero of reception is fixed and two zeros of-reception are capable or"- being altered at will.

It the systems are arranged so that'theline joining them is truly in the direction of the distant station from which it is desired toreceive signals, then all the polar diagrams of reception will be symmetrical.

If, however, the line joining the two systems is not truly in the direction of the sta tion from which it is desired to receive signals, then the polar diagrams-of reception'are asymmetrical as shownin Figure 5. i

Therefore, by suitable arrangement of the two systems relative to the directionaof the station from Whichsignals are' to be received,

and by suitable misphasing of the twMsyss terns when :combini-ng,-'ig reat control canibe obtained over the olar diagram of reception, thereby permitting the elimination of-jznnde sirable signals-and atmospherics; 1 TE/f What we cl'aim isz "P i 11.. In radio signaling apparatusthe' com'bi' nation of a plurality of directional aerials each aerial lbeing constructed tolia-ve also a non-directional characteristic, means for in= dicating oscillations, means for transferring to said indicating means a portion of the energy received by each antenna'by virtue of. its directional characteristic, means -;fortransferring to said indicating nieans a por-' tion of the energy received by each antenna by virtue of its non-directional characteristic. f

2. In radio signaling apparatus the *combi nation of a plurality of direction finding aerials, each direction finding aerial being grounded at a substantially neutral point whereby it has also a non-directional characteristlc, ind cating apparatus, means for impressing upon said indicating apparatus a portion of the energy present in said ground I.

connection and-means for adjusting the phase of the several currents with respect to each other. 1 a 1 3. In a wireless receiving station, the combination of two aerial systems spaced apart and in the general line of desired reception, and each comprising a directional portion and a non-directional portion and a common means for indicating the resultant and the energy received upon each aerialsystem.

4. In a-wireless receiving station, the combination. of a plurality of aerial systems spaced apart-and'in the general line of desired reception and each comprising a pluralityof=aerialzsections, one of said aerial sections'being directive and another non-directive, and a com nionmeans for indicating the resultant; "of-theenergy received upon each aerial 'system i ""53Ifn a1 wireless receiving station, the combination 'offa-plurality of aerial systems spaced apart an appreciable fraction of the wave length of the signals to be received and in the genera'l direction of desired reception,

and: each" comprising a directional portion and a non-directional portion, a common means forindicating the result-ant ofthe energy' received-upon each aerial system and means for regulating the phase of each current component of the energy absorbed by each faerial system to vary the directional characteristic of said station;

In testimony that we claim the foregoing as'our invention we have signed our names this twenty-eighth day of October, 1920.

CHARLES SAMUEL FRANKLIN WILLIAM JAMES PIGKEN. JOHN 'GLOVER ROBB.

CERTIFICATE or connection.

- Patent No. 1,717,674. I Granted June 18, 1929, to

CHARLES s. FRANlQLIN ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction 'a'siifollows: Page 2, line 64, claim 3, for the word "and" read "of"; and that the saidLetters Patent should be read with this correction therein that the same may contorm to the record of the case in the Patent Office. f

Signed and sealed this 10th day of September, A. D. 1929,

M. J. Moore, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF coRasoTioN.

Patent No. 1,717,674. Granted June 18, 1929, to

CHARLES s. FRANKLIN ET AL.

it is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as'lfoliowsz Page 2, line 64, claim 3, for the word "and" read "of"; and that the said-Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 10th day of September, A. D. 1929.

M. J. Moore, (Seal) Acting Commissioner or Patents. 

